Bogged Vehicles

[Wildass69]

And don't be changing the code to "fix" this in CMAK...

Did you conduct tests Redwolf. I'd be interested in your results.

[ November 05, 2003, 12:47 PM: Message edited by: Wildass69 ]

[Redwolf]

I never bothered with checking whether the reverse command increases the chance of unbogging.

I did checks with bogging in general, but not keeping number.

Overall I find the bogging and immobilization chances appropriate in 1.03. There are detail exceptions, though. One example si the StuG III versus the StuG IV. The oversimplified model based soley on average ground pressure over the whole track makes the IV much better than the III, to a point where the III is one of the worst and the IV is one of the best German vehicles. At one point in time I was consuming a lot of StuG literature and I never came across one single remark that the IV was an improvement mobility-wise. Another quirk is that 8-wheel vehicles are better than tracked vehicles which shouldn't be either.

So bogging and immobilization is overall OK with me.

The turn rates however...

Oh, and the Quickbattle generator randomly coming up with non-dry ground (because it has no menu entry for ground conditions) is of course what pisses people so off about the bogging chances. I don't understand why such an anti-fun item couldn't be addressed for CMBB. Maybe we should bitch some for CMAK?

[Wildass69]

I take it that the over simplified model of these two models does not account for the track width (correct me if I'm wrong). I know one of the improvements of the later IVs and consequently their spin-off models such as the Stug IV had wider tracks than earlier models. I'm sure you've considered this but I'd like to hear your thoughts as you seem to have a bone to pick with BF about this. I play a lot of earlier battles so I just haven't run into the Stug IV yet. I know Stug IIIs do get stuck a lot - even more than the Pz IIIs it seems.

I also don't play QBs much as I like the historical aspect of the game and I look for historic battles. So I have not noticed this contention either. In historic scenarios bogged vehicles are distressing enough but I agree that bogging and immobilization in the current version is fine, accurate and doesn't need to be fixed. Nevertheless, like any commander would, I try everything I can to keep every vehicle fighting including the fabled reverse.

It would seem no one has taken the time to see if reversing really does or does not work. In reading through the thread Thin Red Line referenced it's not surprising to find that it has occurred to others to reverse vehicles that become bogged; which substantiates the logic of doing so.

I did not set out to be the first to test this (specifically and in depth) but so far it seems that I am. I would think everyone would be interested to lay this to rest one way or the other for good (fat chance huh?). I don't blame anyone for being skeptical. Ya'll don't know me and you have only my word that I am not given over to fables and mysticisms. I have repeatedly seen this work in my battles and I've even sited a few examples. Otherwise I would not have ventured it to this forum (I don't like to be wrong though I accept that I often am). Certainly I am not the first to suggest that it does. And that should raise the red flags that there may be something to it; it keeps coming up.

The only weapon (of any substance) presented to refute this claim so far has been the word, quoted third hand, from the game's designers. Truly I am not trying to prove them wrong. But just because they say something does not mean the game actually does exactly as they say. 'Tis the nature of the product to be finicky and cantankerous as we've all experienced with many products. We should have a certain reserve about what we are told. No discredit intended.

On the other hand I have presented some numbers and even Sergei's numbers seem to indicate some influence of reversing. Let's at least give it a chance before we summarily dismiss it.

As time permits I'll continue to test. But I don't have to be the only one. If you don't trust what I'm telling you.... well?

WA

[Thin Red Line]

Originally posted by Wildass69:

On the other hand I have presented some numbers and even Sergei's numbers seem to indicate some influence of reversing. Let's at least give it a chance before we summarily dismiss it.

I think your test clearly shows there is no difference between reversing or not.

[JonnyBlademan]

I have had good results if I'm able to push the vehicle onto a road. I have always used reverse while puching and so far have not had the towing/pushing vehicle bog itself, so I think there is something to the reverse order theory (or maybe it's the living sacrifice I make each time I try to un-bog). Oh BTW when I was trained to drive a Bradley, we were taught to do the towing backwards (when possible) because reverse has a lower gear ratio meaning more torque/power. just my .02

[Wildass69]

Oh BTW when I was trained to drive a Bradley, we were taught to do the towing backwards (when possible) because reverse has a lower gear ratio meaning more torque/power.

Exactly! Also it goes without saying that forward motion into whatever has gotten you stuck in the first place is usually not a good idea.

I think your test clearly shows there is no difference between reversing or not.

Of course you do. You probably should stick to the conventional wisdom, TRL. After all there is no difference between 18 vehicles immobilized and 10 vehicles immobilized. But I think the brevity of your statement rips us all off. I said someone would come along and explain it all away but you didn't even do that!

Amused WA

[Redwolf]

Originally posted by Wildass69:

I take it that the over simplified model of these two models does not account for the track width (correct me if I'm wrong). I know one of the improvements of the later IVs and consequently their spin-off models such as the Stug IV had wider tracks than earlier models. I'm sure you've considered this but I'd like to hear your thoughts as you seem to have a bone to pick with BF about this.

Nah, I don't have an axe to grind. My message was clear that I like the overall bogging and immobilization chances in CMBB 1.03.

I am pretty sure CMBB takes the track width into account.

But what it doesn't take into account is:

1) number, distribution and diameter of wheels under the tracks

2) nature of suspension

1) has a large effect and more expert people than me conducted a few threads about it, starting from historical documents explaining the factors. As usual it is hard to find threads on this forum but they were very interesting. Basically the track is actually very far from evenly distributing the pressure, in soft ground the wheels do play a large role and can be "felt" through the track. Furthermore, the angle of the track touching the ground at the beginning of the track plays a big role.

So, while the StuG III has less track surface than a IV, these other factors which are not taken into account would make things more even. The only factor that BFC models is the one with the most difference, so they come out very different. As I said I once read pretty much anything I could get ahold of about StuGs, but I never came around any claim or indication that the IV was a noticeable advance in mobility in difficult ground. I am sure it would have been mentioned if the StuG went from one of the worst to one of the best German vehicles - which it does in CMBO and CMBB.

2), the suspension also plays a large role. A traditional spring suspension has a huge disadvantage: it is not linear. The more you compress the spring the softer it gets. For a vehicle you would want the opposite characteristic, it would be ideal if it gets harder to keep the vehicle stable.

So, if you have a true spring suspension, e.g. the very visible one of the non-HVSS Shermans and you drive over uneven ground, then the vehicle begins to swing, its front and its back sink into the suspension and then back.

But the springs get softer the more they are compressed, so instead of working against the swinging but resisting harder when it kneels in, they become softer, allowing for more kneeling.

So, if you are in soft ground with such a suspension, then the front of the tank is jerked hard into the ground on a regular basis. There is a literal "beating" of the front angle of the track into the mud or sand, creasing a large chance to get the vehicles bogged.

But there are solutions:

1) torsion bar suspension is not subject to this effect. A torsion bar tank will always move much smoother over uneven ground, because the nicking is much more effectively worked against. If the tank nicks in in front, it is is pushed back up into normal position instantly.

2) it also helps to have longer springs and only use part of the room. The spring becomes exponentially much softer at the end of its reserves, so never getting into that region helps a lot.

Again, the StuG III and StuG IV are identical in these factors that are not taken into account, so the difference in CM is bigger than in reality.

The only weapon (of any substance) presented to refute this claim so far has been the word, quoted third hand, from the game's designers.

Well, it wouldn't be the first time that the other BFC people don't precisely know what Charles put it, which is only natural. Hack in our company a lot of programmers don't know what other hackers put in, not to speak of graphics people and the CEO. But your data is just not strong enough to support your claim.

You also have to be careful when reading other threads about bogging and reversing. There once was an actual bug that vehicles in reserve would never bog. A lot of people are not capable of precisely following words, so a myth was created that reversing helps against related to bogging. This might also be a reason why people resist your claim so violently, although you obviously understand the difference between bogging chance and immobilization after bogging chance.

[Wildass69]

What German vehicle was the worse on the battle field. I'm under the impression that the Mark IV was pretty bad about getting stuck. It would seem then that the Stug IV would be about the same. Of course I'm talking all track vehicles.

But your data is just not strong enough to support your claim.

Thanks for the heads up about how threads can be somewhat mis-leading or vague when talking about reversing - I've noticed. I think we all get a little careless because we're each in a hurry to espouse our views!

I'll grant you that one battery of tests against one vehicle is not conclusive. But I would argue that it by no means dismisses my "claim". Certainly it offers the possibility that there is something to reversing as opposed to so many good folk simply saying that there isn't. Certainly it's strong enough to warrant pursuit of the matter. In the long run this will tell one way or the other. I don't like to be wrong. But if I am, so be it.

WA

[flamingknives]

redwolf, you keep mentioning an effect, example below:

2) it also helps to have longer springs and only use part of the room. The spring becomes exponentially much softer at the end of its reserves, so never getting into that region helps a lot..

In a coil spring, the force acting to restore the spring gets larger the more it is compressed. The stiffness remains constant throughout compression, until the spring is fully compressed, when it becomes stiffer (or harder) but not softer.

This effect also occurs under tension.

The 'bouncing' effect seen as vehicles pitch violently is symptomatic of poor or absent shock absorbers.

[Wildass69]

I'm just guessing but aren't most springs on WWII AFVs leaf springs? I gathered from how RW talked that he was discussing leaf springs.

[Redwolf]

I have to swap in my info again, I once absorbed this when reading about torsion bar suspension advantages.

Leaf springs are set up in stacks with different length of sheets to work against this effect, I am not sure how effective that is. You might be right.

It might be that it doesn't get softer linearily (which is obviously not the case for coil springs), but that the increase in hardness is not linear, i.e. the first derivation falls off.

In any case, the torsion bar's biggest advantage is supposed to be a better pattern of resistence against kneeling in (not aginst nicking as in osccillating which as you say is a result of bad shock absorbers, but against jerking in once). So the tank's hull stays more stable which is good for efficency (not losing kinetic energy from bumping) and also for mobility because you don't push edges of the tracks into the ground.

[PJungnitsch]

Originally posted by redwolf:

But what it doesn't take into account is:

1) number, distribution and diameter of wheels under the tracks

2) nature of suspension

If you want to get more into this the papers are posted on my web page here. (You may have to wait a while, free web file hosting has its limitations). The measure BTS uses is called nominal ground pressure, NGP, which uses only weight and track area. This is a very easy to figure out method but is really only accurate on a concrete floor, where ground pressure is not usually an issue.

MMP, mean maximum ground pressure, measures the pressure spikes the track places on the ground (since it is flexible and not a solid bar). The less sections the track has and the better supported it is the better the tank will actually 'float' over soft ground. This concept was not well understood and resulted in things like the Kingtiger having twice the floatation of the Elephant, despite having approx the same weight.

It's one reason why commercial bulldozers have long track links and lots of small track support wheels compared to military vehicles. It's a low speed suspension, but it floats extremely well.

[Thin Red Line]

Originally posted by Wildass69:

Of course you do. You probably should stick to the conventional wisdom, TRL. After all there is no difference between 18 vehicles immobilized and 10 vehicles immobilized. But I think the brevity of your statement rips us all off. I said someone would come along and explain it all away but you didn't even do that!

Look at your numbers. All they show is that you CAN immobilize a vehicule in reverse ; the sample isn't large enough to prove anything else.

I've heard this reverse tales since CMBO and it never proved true from the dozens of tests conducted by curious minds, and my own experience .

Your test failed to convince me. I just gave my opinion on them, i'll not do it anymore if you prefer. Sorry to have interfered in your thread .

About the brievity of my comments, i apologize, english isn't my native language so sometimes i just prefer being short. I didn't know there was a minimum number of words requested to answer .

To take the words in someone else's mouth :

Originally posted by Sergei:

Dear W69, don't be offended for nothing...

[ November 11, 2003, 08:53 AM: Message edited by: Thin Red Line ]

[Wildass69]

TRL, I'm sure others have conducted test. Including you. But this thread has been around a little while and I think I've asked if anyone else has conducted such tests. No one has offered anything other than BFC has said it doesn't make any difference. That's even less proof than my anemic numbers. Did you say you've conducted these very tests? I don't recall that you did but I could be wrong. And if you did where are your results?

These tests don't prove vehicles can be bogged in reverse! They are not suppose to. None of the vehicles bogged in reverse because the only time any of them were in reverse was after they had already bogged! The point of the tests is to see if reversing a vehicle that has already bogged will unbog it. Now I'm asking you point blank; have you tested to see if a vehicle will unbog if you put it in reverse after it has already bogged? I've said this enough times that I'd think you would understand what I'm trying to do even if English is not your primary language.

My initial numbers DID indicate something seems to be happening when I reverse a bogged vehicle. But your understanding of my numbers seems dubious so I'll take back my smartass reply.

I don't care if anybody believes reversing works. I do care about the truth. I do not appreciate being dismissed as one who believes in myths. And most of all I do not appreciate closed mindedness about it. The reason this has been going on so long is because no one has tested it enough AND published a report that everyone can turn to when a newbie comes along and says what I said at the beginning of this thread.

If I'm wrong I will admit it. And I'll tell you now that subsequent tests I've been conducting have not been encouraging for my position. But the truth is the truth and I will tell it no matter how wrong it makes me.

You all will hear it all when I'm done - whatever "all" is!

Grounded WA

[Wicky]

Originally posted by Wildass69:

edited lots of stuff out

Here's a link to Joeri's Original post in which he announced his discovery of the 'original' no-bogging in reverse bug.

Most relevent (admittedly referring to CMBO in 2000) is his comment in the final post and his use of a smiley

"About the unbogging techniques. Someone from BTS posted somewhere that you best do nothing while bogged and let the crew sort it out. By the way, unbogging chance is approx 75% (according to my test) so seeing all your vehicles unbog is not so unlikely. Unless you have had a very high number of occurences. I used to do the same trick (stopping and reversing) and it worked often(in approx. 75% of the time )." Archive Link

And another link in which he sets out statistical probabilities of bogging in various terrain types as an example of his thorough methodology and analysis. Archive Link

"IIRC this has been commented upon by the new BTS member MadMatt and he said that player action has no effect on whether a vehicle frees itself or becomes immobilized."

barrold713, Oct 6 2000

Archive Link

[ November 13, 2003, 05:11 AM: Message edited by: Wicky ]

[Thin Red Line]

Originally posted by Wildass69:

These tests don't prove vehicles can be bogged in reverse! They are not suppose to. None of the vehicles bogged in reverse because the only time any of them were in reverse was after they had already bogged! The point of the tests is to see if reversing a vehicle that has already bogged will unbog it. I've said this enough times that I'd think you would understand what I'm trying to do even if English is not your primary language.

It is what i understood, hence let me reword it : your tests (until now) do not prove that using the reverse order increase the debogging probability. That's all what i meant, i thought you were asking opinions on your tests but i'm sorry if my opinion offended you.

[Wildass69]

Those are very interesting links, Wicky. Joeri's tests are related to what I am doing although he did not get into the same issue I am investigating. Unfortunately only one of the posters specifically address the issue that I have been testing. His observations were made only during a game - not a dedicated test. It would be interesting to see how Madmatt came to his conclusion that you are better off leaving the vehicle completely alone (I disagree, in that, I have not seen reversing a vehicle harm the process though the jury is still out on whether it really helps - so leaving it alone may only be "best" in terms of how much you want to bother with it.) This isn't about the old reversing bug where vehicle would not bog while traveling in reverse. (I keep seeing this here and I don't know how else to make this clear). This is about getting a bogged vehicle to unbog by changing it's move order to reverse. I'm looking for data from tests on this specific issue. I haven't seen any other than what Sergei offered several posts back.

TRL, you didn't offend me and I'm not trying to discourage you from offering your opinion. However it was a bit frustrating because you summarily dismissed what, IMO, was obvious. At least between those two tests there was an obvious difference and a strong suggestion that reversing did help unbog vehicles. And I'd already admitted one battery of tests were not enough. You offered no reasoning why you felt my numbers did nothing. I understand your reason for that but, it doesn't relieve you of the responsibility of explaining why you felt that way, to the rest of us. Don't go away just because I'm a cranky ol' curmudgeon.

I do have another theory that pertains to why these types of tests are deceivingly difficult and the results may be very hard to distill into fact. And to why it may appear reversing helps when maybe it doesn't really. (See? I can be swayed with real results!). I have noticed a tendency in my computer to "remember" a previously played battle and it's propensity to change the previous results. This seems to be apparent when I repeat a turn by reloading autosave or a saved iteration. This may go to the game engines randomizer. The problem this seems to create is that it forces different results to the same circumstances. This means that when a vehicle bogs in the initial play of the battle it probably will not bog if you replay that turn. Likewise if you leave the vehicle alone in one turn and it immobilizes you will probably find that if you replay that turn and reverse the vehicle it will unbog instead.

What am I getting at? Because of this possibility the results of each subsequent test from the same battle scenario are getting progressively outrageous because the randomizer is avoiding previous results. My fix for this problem might be to rename the original battle in the Scenario Editor every time I run a test. This could turn out to be something of a pain in the wildass. But what we want are pure results. If that doesn't work it may require rebuilding the battle every time - a prohibitive endeavor! Any thoughts?

Remember it's just a theory - I'm not married to it.

Frustrated WA

[Wicky]

Please read carefully again, until you comprehend his ironic conclusion:

"About the unbogging techniques. Someone from BTS posted somewhere that you best do nothing while bogged and let the crew sort it out. By the way, unbogging chance is approx 75% (according to my test) so seeing all your vehicles unbog is not so unlikely. Unless you have had a very high number of occurences. I used to do the same trick (stopping and reversing) and it worked often(in approx. 75% of the time )."

Digging deeper in the archive:

Moon wrote Dec 30 1999:

"I had to check back with Charles* about it to be sure, but a unit's order have no influence on its chances to "un-bog" or get stuck for good. Once bogged, a vehicle will try to free itself asap and disregards any order it has until it has done so or is immobilized (by throwing a track, driving even deeper into the mud etc.) "

* The brain in a jar

[ November 13, 2003, 02:00 PM: Message edited by: Wicky ]

[tar]

Re: Reversing and Unbogging.

For starters, I would be quite willing to take the word of the game programmer that there is no effect on the chances. If there were any true connection, it would have to be programmed into the game. If there isn't any code to make the influence happen, then it just won't happen.

Secondly, I finally broke down and ran the statistical analysis on Wildass's reversing findings. The summary information is as follows:

Reverse: 11 immoblized, 25 freed

No Change: 18 immoblized, 20 freed

I used this matrix to run a chi-squared test for the statistical significance of the results. The chi-squared value had a probability of 0.13 which does not meet the required 0.01 or even the looser 0.05 standard for statistical significance.

What that means is that the sample size is too small to be able to rule out expected random variation as the cause of the results.

Now, what would be the required sample size to show the difference? If one assumes that the ratio remains the same (in other words, that these results are exactly the difference in chances), then running a sample 4 times the size should produce a significant result. (3x comes close, but 4x would be better).

[Wildass69]

Thanks, Wicky, but I already understood the "irony". I just didn't consider the simply percentage of 75% to be meaningful without any information or numbers from his tests to back it up. No offense intended. But since I was more or less goaded into this mire of perpetual testing I feel that "data" should loosely equal something comparable to what I'm currently bogged with. You understand. I did mention I'd like to see Madmatt's tests...

Tom your response is significant. Thanks for taking the trouble. I'm not an analyst of statistics but I do understand in layman’s terms that the information I've provided so far is inadequate to fully develop any factual results. I'm working on it. The problem I'm running into is as I related in my last post: the computer seems to remember the previous run of the "battle". This appears to influence each following test because my numbers are getting more radical each time I run the test. Also it would seem that I'm going to have to split the vehicles into two groups and reverse one group while leaving the other untouched all during the same battle in order to get a more accurate comparison. While there may be a mean percentage that governs bogging it does seem to fluxuate from battle to battle. (Nothing of the circumstances - terrain type, vehicle type, time frame etc. - has been altered from the beginning). What we need is a constant testing bed in order to get a fair assessment of what's really happening. In other words, I suspect each test must be conducted from a new battle that the computer has never "seen" before. (Hopefully just a name change to the file).

As much as I hate to admit it that may be an explanation of why my first two tests were so different. This could also explain why some of the events I've encountered in playing battles seem to strongly suggest the usefulness of reversing in the first place. But we're here to find all that out.

Another possible solution might be if 10 different computers (Ahem... meaning 10 volunteers) all ran the same exact, split group, test just once each and the data then analyzed by a Tom Russ type independent of the 10 testers.

Detective WA

[Wicky]

I wouldn't say you were goaded in testing, you made a rather rash statement and people asked for proof to back it up. You've accepted the challenge and now you're trying to penetrate into the murky 'Mind Of Charles' which has driven many a mortal* to madness, just like the scientists in Gullivers Travels who tried to extract sunshine from cucumbers

But who knows, like Columbos you might be aiming for China but will discover the Americas instead.

*Joeri vanished in January 2001 just a couple of months afer announcing his discovery, his last unanswered post questioned the AI's sanity in mine placement.

[tar]

Well, there is also the confounding influence of both the pseudo-random number generator in the computer or in CM itself. I don't know if CM uses its own generator or the one that comes in the [insert programming language] library. There is also the issue of how the pseudo-random numbers are manipulated in the game.

Some types of random number generator have bits that are not always as random as the number as a whole. Depending on how one uses the results, one can end up with highly non-random results. (The worst case is if it turns out that the random numbers alternate between even and odd. If you only look at the last bit, you get a perfectly predictable sequence!).

[Wildass69]

I wouldn't say you were goaded in testing, you made a rather rash statement and people asked for proof to back it up.

I have chosen to take your comments as encouragement (whether that's the rational or not). The goaded comment was an exaggeration I expected to be taken tongue in cheek and note that I did not specify who goaded me(choose one; comments about mythology; my own pride; innate curiosity). And as to being rash, that's a matter of perspective isn't it?

I certainly did not expect this outcome when I offered my "tip". I should have known better. I probably wouldn't have if I could have foreseen this harrowing trip into the Para-lucid mind of an irascible programmer who is apparently ensconced in the Point-Five dimension of Ones and Zeros; no offense intended.

My condolences to Joeri's family.

And if so fated to discover, as did Columbus, I'm sure there will be some group out there to protest any of my accomplishments. Enough encouragement!

Basically, TAR, I hear more clearly than ever the need for at least 7 volunteers to take this test and run it just once on their respective "virgin" machines; preferably with various OS's. Computer programs are based on Mathematics, the antecedent of chaos and random-ness, so what else can we expect - trying to force something so logical and scientific to be something that it is not?

Anyway, this weekend I will try to set up a new series of tests finally grappling with the for mentioned suspicions. Not really expecting any volunteers, I figure I'll continue this Gulliveresque endeavor solipsistic.

jazzed WA